Many growers in the United States are currently switching from conventional tillage methods or minimum tillage methods to zone or strip tillage methods to reduce input costs and increase crop yields. The strip tillage machines currently on the market are designed to perform zone tillage, apply product such as fertilizer, and make a mellow, friable seedbed for the upcoming crop. Residue levels for strip tillage range from light soybean stubble to heavy standing corn stubble.
Individually mounted front coulters are typically used with most conventional strip tillage machines. New corn hybrids with taller and stronger stalks increase problems of residue management with the strip tillage practices. An extra pass with a coulter cart or stalk chopper is often required to promote decomposition and help residue flow through the conventional strip tillage machines. A strip tillage machine that eliminates the extra pass is desirable to increase productivity.
Strip tillage row cleaners that clear residue off a strip of ground typically eight to ten inches wide must be able to operate in the tough, heavy corn residue conditions. Cleaners on conventional strip tillage machines may not have sufficient aggressiveness and residue flow capacity for the high residue conditions in corn stubble and the like. Also, the cleaners must be able to move vertically over obstacles. Providing an aggressive strip tillage row cleaner assembly with satisfactory trip and residue clearance has been a continuing source of problems. If the clearing disks fail to remain in a generally level attitude during vertical movement, efficient trash clearing and residue shedding characteristics can be compromised.
Trailing covering disks in strip tillage machines are designed to catch the dirt spray off a forwardly mounted tool such as a fertilizer knife and move the dirt back over the row to seal the applied product and make a berm. Some machines have floating closing disks while others include closing disks set to operate at a set depth. In some implements, short closing arms connected by a support located closely adjacent the earthworking tool cause severe twisting moments in the assembly in uneven ground conditions, and trash cannot effectively clear behind the tool causing plugging and slugging. Short arms adversely affect the working angle of the disks as the closing disks rock vertically.
Often conventional strip tillage machines fail to provide simple adjustments to vary characteristics of the strip till berms such as berm size and berm shape to accommodate varying field conditions on-the-go. For example, current adjustments may be inadequate if the operator encounters sandy conditions wherein the closing disks operate too deeply and cause plugging and unsatisfactory berms. Providing a single-pass strip tillage machine that is operable in heavy corn stubble, easily adjusted on-the-go, and compact in design has been a source of difficulty.